Workpieces, such food products, often vary in physical properties. The variation in physical properties may be economically significant from piece to piece. More specifically, the value and end use of a workpiece may depend in whole or in part upon the physical properties of the workpiece. In the case of a food product, tenderness, texture, stiffness, time dependent strain, resilience, or other physical properties are commercially important measures of quality.
Food products are often processed in motion on a conveyor system. Thus, any scanning, measurements, and other processing (cutting, trimming, slicing, etc.) must occur while the workpiece is in motion. After any preliminary processing occurs, the workpieces must also be unloaded, transferred, purposefully left on the conveyor, or moved into a desired location for subsequent processing, such as marinating, breading, cooking, cooling, packaging, etc.
Processing a food product or other workpiece while it is in motion presents many challenges. For instance, in some applications, the apparatus that is processing the workpiece may need to move along with the workpiece while performing the processing step. In addition thereto or in the alternative, the apparatus must process the workpiece so quickly that the motion of the workpiece is uninterrupted. Moreover, the workpiece must be processed quickly to ensure that it is finished before subsequent processing occurs.
In the specific example of a food product such as chicken, the chicken may be scanned to determine its shape and size, it may be sorted based upon product attributes, it may be portioned or cut into a desired shape or size (before or after sorting), and it may be off-loaded for further processing. Technology exists for scanning, sorting, portioning trimming, and/or unloading a food product such as chicken while on a moving conveyor system. An example of such a system is shown and described in U.S. Patent Application Publication No. 20150205288, entitled “System for Cutting and Unloading Portions”, filed on Jan. 22, 2014, the disclosure of which is hereby incorporated by reference in its entirety.
However, it would also be useful to test and assess the physical properties of a workpiece in motion to determine the quality and/or use of the workpiece. As an example, certain pieces of chicken breasts may be suitably tender for consumption without the need for significant processing, while other pieces may only be suitable after further processing, such as brining, tenderizing, etc. Moreover, certain pieces may be so poor in quality that they must be discarded.
For instance, white striping and hard or “woody” texture has been observed in some chicken breast muscles. This chicken product, referred to as “woody chicken,” is leading to customer complaints. The woody chicken is typically a very stiff meat that can be used in limited applications, or perhaps not used at all. Thus, a need exists for testing and assessing the physical properties of a workpiece, such as the viscoelastic or resilience properties of chicken breasts, while the workpiece is in motion, for determining the end use of the chicken and/or for identifying workpieces that must be discarded. The unit of resilience can be calculated, for example, using the area beneath a measured stress-strain (σ-ε) curve.
Current technology exists in lab, table top or batch format to assess fruit quality or meat tenderness. Typically these lab systems employ fixtures that have a long cycle time (e.g., about 1 minute per piece), and the fixtures destroy the workpiece during the test. Moreover, the lab fixtures are not suitable to test the workpieces as they are moving.
Moreover, it should be appreciated that the temperature of the workpiece may affect its measured viscoelastic properties. For instance, a chicken breast that is frozen (100% ice crystals) will be significantly stiffer than a chicken breast that is partially frozen (in the latent zone) or thawed (0% ice crystals). Thus, a further need may exist for measuring and accounting for the temperature or energy content of the workpiece in motion when assessing the physical properties of a workpiece in motion.
The present invention automates the physical assessment of workpieces, such as chicken breasts, in a non-destructive, 100% inspection, high-speed, continuous flow system. More specifically, in one aspect, the present invention involves scanning the workpiece to identify one or more region of interests, guiding a measurement system to a region of interest, measuring physical attributes at the region of interest on the workpiece while the workpiece is in motion, and recording the measured information for the selected workpiece for subsequent use and optionally acting upon the measured information. In another aspect, the present invention involves scanning the workpiece to identify one or more region of interests, measuring physical attributes at a region of interest on the workpiece while the workpiece is in motion, and recording the measured information for the selected workpiece for subsequent use and optionally acting upon the measured information.